Proximity warning system



Jan. 26, 1965 A J. B. FAIRBURN PROXIMITY WARNING SYSTEM Filed March 5,1963 INVENTOR. A JOHN B. FAIREURN Attorney United States Patent3,167,753 PROXIMITY WARNING SYSTEM A John B. Fairburn, Lorain, Ohio,assignor to United States Steel Corporation, a corporation of New JerseyFiled Mar. 5, 1963, Ser. No. 262,905 2 Claims. ((21. 340-441) Thepresent invention relates generally to signal devices and, moreparticularly, has as its primary object the provision of an improvedproximity warning system for signalling the approach of a vehicle comingwithin collision range of another vehicle or object.

It is a more specialized object of my invention to provide a pneumaticproximity warning system in which a blower delivers a jet air stream tooperate a switch to actuate an alarm when a vehicle approaches collisioncourse with another vehicle or object.

It is another object of my invention to provide a proximity warningsystem of the character described which can be easily installed andoperated on existing equipment.

It is a further object of my invention to provide a proximity warningsystem as set forth above which can be assembled with relativelyinexpensive, readily available materials.

These and other objects will become more apparent after referring to thefollowing specification and attached drawing, in which:

FIGURE 1 is a diagrammatic showing of the transmitter and receivercomponents of the system of the invention installed on two overheadcranes operating on a common trackway;

FIGURE 2 is a schematic illustration of the electric circuit of thetransmitter component of the system of the invention; and

FIGURE 3 is a view similar to FIGURE 2 showing the electric circuit ofthe receiver component of the system of the invention.

Although the present invention is hereinafter described in detail as itwould be applied to and used in conjunction with the operation ofoverhead cranes, this is done by way of example for illustrativepurposes only and it is to be understood that the system of theinvention can be used with equal effectiveness with other vehicles.

Reference numeral 2 designates an overhead crane track having two cranes4 and 6 mounted for travel therealong. The proximity warning system ofthe invention includes a transmitter component which is mounted on crane4 and a receiver component which is mounted on crane 6.

The transmitter component includes an air blower 8 directly coupled to adrive motor 10. The blower 8 is driven continuously to discharge a jetair stream 12 directed toward crane 6 while the cranes are operating.

The receiver component on crane 6 includes a box 14 which houses anormally-open air-actuated mercury capsule switch 16 of the typedisclosed by U.S. Patent No. 1,720,180. The box 14 is open on its sidefacing crane 4 and is so disposed on crane 6 that switch 16 ispositioned to be actuated by the jet air stream 12 when either craneapproaches within collision range of the other. If the cranes approachwithin collision range, the jet air stream 12 strikes the vane of switch16 and causes it to tilt the capsule and close the contacts of theswitch. The switch 16 is connected in series with bell alarm 18 andbattery 20 so that when the switch 16 is closed by action of the jet airstream a circuit to the bell alarm is completed through the battery 20and the bell, which is preferably located inside the operators cab 22 ofcrane 6, is energized by the battery and caused to ring. Although I haveshown the use of a bell as an alarm in the receiver component, it willbe understood that other sensory 3,167,753 Patented Jan. 26, 1965perceptible means, such as signal lights, horn, etc., could be used asthe alarm, as desired.

The electrical circuit of the receiver component of the assembly of theinvention is shown schematically in FIGURE 3, and its operation isthought to be clear from the foregoing description.

As an added safety measure, [the transmitter component of the assemblyof the invention may be provided with means for signalling the craneoperator of the crane on which the transmitter component is carried inthe event that the blower 8 fails to function and a jet air stream isnot being generated. Such means includes a normallyclosed air-actuatedmercury capsule switch 24, of the type disclosed by U.S. Patent No.1,720,180, disposed on the crane 4 in the path of the jet air stream 12.The switch 24 is connected in series through a battery 26 with a buzzeralarm 28 located in the operators cab 30 of crane 4. Switch 24 istiltably mounted so that it will remain open so long as the jet airstream 12 is flowing. If the air stream should fall for any reason, theswitch 24, no longer restrained by the air stream, will tilt due togravity and close. Closing of switch 24 will cause a circuit to becompleted to the buzzer 28 through the battery 26. Sounding of thebuzzer in the cab 30 will alent the crane operator to the fact that thewarning system is not functioning properly. A manual switch 32 may beprovided in the circuit between the switch 24 and the buzzer 28 so thatthe circuit can be interrupted when the crane is idle.

The complete electrical circuit of the transmitter component of thesystem of the invention is shown schematically in FIGURE 2. Power sourceL L supplies current to motor 10 through a manually-operated switch 34to drive the blower 8 to generate the jet air stream 12. Switch 24 isdisposed adjacent the mouth of the blower 8 in the path of the airstream and is connected in series by means of a separate circuit withthe buzzer 28, battery 26 and the normally-closed manual switch 32. Asexplained above, normally-closed switch 24 is kept open by the airstream and if the air stream fails, switch 24 closes and a circuit iscompleted to the buzzer 28 through battery 26 to actuate the buzzer.Switch 32 is opened to maintain the circuit between the switch 24 andbuzzer 28 open when the equipment is idle. The circuit as shown inFIGURE 2 shows switches 32 and 34 open and switch 24 closed as theywould be when crane 4 is idle. When crane 4 is operating, manualswitches 32 and 34 are closed and mercury switch 24 is open so that thealarm system is in operation.

If desired, complete transmitter and receiver components of the warningsystem of the invention can be installed on each crane. Such a dualinstallation would provide an additional safety factor since each craneoperator would be warned simultaneously if the cranes approached withincollision range.

Although I have shown the system of the invention as used installed ontwo moving cranes, it will be understood that the system could also beused on a moving vehicle and an immobile object, such as on a crane andthe end-of-track bumpers on the crane trackway, to give warning if themoving vehicle approaches too closely to the immobile object.

While I have shown but one embodiment of my invention, it will beapparent that other adaptations and modifications may be made withoutdeparting from the scope of the following claims.

I claim:

1. In a vehicle and an object approachable by said vehicle theimprovement therewith of a system for warning of the proximity of saidvehicle to said object, said system comprising a transmitter on one ofsaid vehicle and said object and a receiver on the other of said vehicleand said object, said transmitter comprising means for generating a jetair stream directed toward said receiver, said receiver including analarm, and an airactuated switch controlling said alarm, said switchbeing positioned to be actuated by said jet air stream and completing acircuit to said alarm when said transmitter is within a predeterminedproximity of said receiver.

2. The improvement as defined by claim 1 in which said transmitterincludes an alarm, and a normally closed air-actuated switch controllingsaid alarm, said switch being disposed in the path of said jet airstream and normally held open thereby, said switch completing a circuitto said alarm in the absence of said jet air stream.

No references cited.

1. IN A VEHICLE AND AN OBJECT APPROACHABLE BY SAID VEHICLE THEIMPROVEMENT THEREWITH OF A SYSTEM FOR WARMING OF THE PROXIMITY OF SAIDVEHICLE TO SAID OBJECT, SAID SYSTEM COMPRISING A TRANSMITTER ON ONE OFSAID VEHICLE AND SAID OBJECT AND A RECEIVER ON THE OTHER OF SAID VEHICLEAND SAID OBJECT, SAID TRANSMITTER COMPRISING MEANS FOR GENERATING A JETAIR STREAM DIRECTED TOWARD SAID RECEIVER, SAID RECEIVER INCLUDING ANALARM, AND AN AIRACTUATED SWITCH CONTROLLING SAID ALARM, SAID SWITCHBEING POSITIONED TO BE ACTUATED BY SAID JET AIR STREAM AND COMPLETING ACIRCUIT TO SAID ALARM WHEN SAID TRANSMITTER IS WITHIN A PREDETERMINEDPROXIMITY OF SAID RECEIVER.